<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8" />
  <meta http-equiv="X-UA-Compatible" content="IE=edge" />
  <meta name="viewport" content="width=device-width, initial-scale=1.0" />
  <title>Document</title>
  <style>
    .box {
      width: 500px;
      height: 500px;
      background-color: #ccc;
      color: #fff;
      text-align: center;
      font-size: 100px;
    }
  </style>
</head>

<body>
  <div class="box"></div>
  <script>
    const box = document.querySelector('.box')
    let i = 1
    function move(){
      box.innerHTML = ++i
    }
    function throttle(fn,t){
      let timeId
      return function(){
        if(timeId) clearTimeout(timeId)
        //开启定时器
        timeId = setTimeout(function(){
          fn()
        },t)
      }
    }
    box.addEventListener('mousemove',throttle(move,1000))
    // throttle(move,1000) ===  function(){console.log(1111)}
  </script>
</body>

</html>